#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<vector>
using namespace std;
class Solution {
public:
    int findKthLargest(vector<int>& nums, int k) {
        srand(time(0));
        return qsort(nums, 0, nums.size() - 1, k);
    }
    int qsort(vector<int>nums, int l, int r, int k)
    {
        if (l == r) return nums[r];
        int key = getRandom(nums, l, r);
        int i = l, left = l - 1, right = r + 1;
        while (i < right)
        {
            if (nums[i] < key) swap(nums[i++], nums[++left]);
            else if (nums[i] == key) i++;
            else swap(nums[i], nums[--right]);
        }
        int b = right - left - 1, c = r - right + 1;
        if (c >= k) return qsort(nums, right, r, k);
        else if (c + b >= k) return key;
        else return qsort(nums, l, left, k - b - c);

    }
    int getRandom(vector<int>nums, int left, int right)
    {
        return nums[rand() % (right - left) + left];
    }
};